24 MICROBIOLOGY 



In the beginning the protoplasm of the elongated filaments 

 is homogeneous, but after a time it becomes turbid and 

 finely granular. These fine granules are then replaced by 

 a smaller number of coarser granules, which are finally amal- 

 gamated into a spherical or oval refractive body. This is 

 the spore. For a time the spores are retained in a linear posi- 

 tion by the cell membrane of the bacterium, but this is later 

 dissolved or broken and the spores are set free. Spores are 

 not formed in every individual organism. This species loses 

 its property of forming spares when grown under a high 

 temperature (43 C.). 



Types of spore formation. The following are the most 

 important types of spore formation: (1) the spores lying in 

 the interior of single, undist ended organisms; (2) the spores 

 lying in the interior of a chain of undistended organisms; 

 (3) the spore lying at the extremity of the organism much 



Fig. 9. Speculation and germination of spores. 1, formation 

 of spores; 2, direct germination; 3, polar germination; 4, equatorial 

 germination. Highly magnified. 



enlarged at that end the so-called "head spore"; and (4) 

 the spore lying centrally in the interior of an organism which 

 is much enlarged in its central portion, giving it a spindle 

 shape. 



Spores may be considered as the resting stage or form 

 of the bacteria which produce them, i. e., the spores are en- 

 abled to remain alive under life conditions that would de- 

 stroy the vegetative forms. 



Spore germination. When the spores are brought 

 under favorable life conditions they absorb moisture and 

 germinate. This process is not the same for all species. In 



